BRONWYN HERBERT: The Energy Users Association of Australia represents resource and mining companies as well as businesses using plenty of electricity.

The group commissioned a consultancy to look into the result of renewable energy policies over the past decade.

Bruce Mountain is a director of Carbon Market Economics and led the study.

BRUCE MOUNTAIN: So, wind generators attracted roughly half of all the subsidy dollars, which one certainly would have thought ought to have been much higher, because wind generation is by far the cheapest.

The stand out issue is solar PV, which is principally PV on household roofs, which attracted one third of the total subsidy, which was far, far greater than it ought to have in terms of its costs, which are roughly 10 times that of wind.

BRONWYN HERBERT: Is it a fair argument that to help build a new industry, like the renewable sector, there needs to be some type of incentive or support from a government to really get it off the ground and make it a viable alternative?

BRUCE MOUNTAIN: Yes, I think there certainly is a reasonable argument. I think the issue is ensuring that the subsidy is allocated as well it might be; so is the subsidy going to the cheapest cost sources, is the subsidy being managed well, who's bearing the subsidy, is it energy users, is it taxpayers? Who optimally ought to be bearing the subsidy?

Those are all the questions and I think those questions haven't been adequately addressed.

BRONWYN HERBERT: Bruce Mountain says wind is likely to be the bulk provider of renewable power to meet Australia's 20 per cent target by its deadline of 2020.

BRUCE MOUNTAIN: It has a cost advantage over the other technologies by a very significant margin. There's a lot of prospect for solar thermal technologies and other solar forms, but as yet, they don't have unit costs anywhere near as low as wind.

BRONWYN HERBERT: What's the difference in prices?

BRUCE MOUNTAIN: The latest indication I've seen is that levelised unit costs, or the average cost of production, which includes a capital cost of wind is typically around half the price of other major scale alternatives.

BRONWYN HERBERT: And he puts that cost at just over $30 billion.

BRUCE MOUNTAIN: Our sums seem to suggest that around $30 billion as a capital sum needs to be spent on the generators alone in order to meet the targets. Further investment will be needed in the networks and in other forms of power generation as a stand-by back up to the clean energy generators.

BRONWYN HERBERT: The executive director of the Energy Users Association, Roman Domanski, says it'll be consumers who pay through their power bills.

ROMAN DOMANSKI: Consumers are being asked to pay for the great bulk of the cost of these things, yet you know they don't derive direct benefits from it, in terms of developing the wind or the renewable industry.

BRONWYN HERBERT: But the renewable energy sector says that when that figure's broken down as a cost per household it's relatively affordable.

Matthew Warren is the chief executive of the Clean Energy Council.

MATTHEW WARREN: I mean our modelling shows it's around about in total $1 to $1.30 a week per household, is the cost of renewable energy target and associated policy in 2011. So it's how you depict the number, but it's a prudent investment we think in Australia's energy future.

MATTHEW WARREN: Yes, renewables are a contributing factor to power price increases as they've been gently over the last decade but by far and away the majority of those increases are and will continue to be driven by network charges.

BRONWYN HERBERT: The report concludes that the cheapest renewable technology is wind generation.